[Request] Random Cars and Such on Road

Hello everyone :D.
Great forum here, I have been lurking about this site for the past 5 months :D, it has helped me numeriously.

Thanks for that :D.

Anyways, I am making a little navigation and I needed some help.
I am creating a city, and I have a road. I want to be able to randomly create either movieclip1, movieclip2, movieclip3 or movieclip4, (which could be different cars and automobiles) and have them start moving on the road. When they reach the end, they disappear.

I was thinking, for each movie clip, I could use motion tween, but I somehow need these 4 movie clips to be created randomly.
Any help would be appericated. Thanks.

Lets hope, you can manage to understand with my quick two-and-a-half minute doodle :P. Edited the image a bit to make it clear-er :stuck_out_tongue: